Understanding top output in Linux

Posted by Rayne on Stack Overflow See other posts from Stack Overflow or by Rayne
Published on 2010-04-08T04:11:19Z Indexed on 2010/04/08 4:13 UTC
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top

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linux

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cpu

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utilization

Hi,

I'm trying to determine the CPU usage of a program by looking at the output from Top in Linux. I understand that %us means userspace and %sy means system/kernel etc. But say I see 100%us. Does this mean that the CPU is really only doing useful work? What if a CPU is tied up waiting for resources that are not avaliable, or cache misses, would it also show up in the %us column, or any other column?

Thank you.

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